We have our maintenance department drill right through the platters... but, something makes me think the discs still need to be intact after this is done.... 4 drives in under an hour, I'd make sure you can do them all at the same time... get a multi-drive dock if mobile, or prep a desktop to take all four and find a utility you can run on multiple discs at once.

The next question is how 'wiped' do they need to be/what are the disks going to be used for next? A quick format will only take a few minutes, but re-writing the disk with random data a few times will probably take hours.

The next question is how 'wiped' do they need to be/what are the disks going to be used for next? A quick format will only take a few minutes, but re-writing the disk with random data a few times will probably take hours.

Exactly.

1 hour and 2TB doesn't divide very well - at most you'll be doing a quick format or doing a pass over some of the disk.

well there is the problem that the hardware doesn't belong to us but the court has given us permission to wipe the HD

So, nothing destructive, and based on the whole 'court' part, no chance of recovering data for sure... Marcin's suggestion with direct SATA connections then, and for 4 disks too... you're going to need a desktop.

You might request instead of wiping the drives, offer finances for a same-model replacement... you take the disks, give them money for new disks. Problem solved.

*Edit* I wasn't watching my 'disC/disK' usage, and I meant to add that for something under a few hundred and since lawyers are involved, I'm assuming your company approving of the cost won't be in question.

Well it's really this simple - in 1 hour with a 2TB hard drive, other than total physical destruction, you aren't going to wipe it properly to the point where someone with the right tools couldn't get stuff off it.